Herbicidal Composition Comprising and Aminophosphate or Aminophosphonate Salt and a Betaine

ABSTRACT

The present invention relates to herbicidal compositions comprising an aminophosphate or aminophosphonate salt, particularly to herbicidal compositions comprising a relatively high amount of aminophosphate or aminophosphonate salt and a betaine-based surfactant composition of mater.

BACKGROUND OF THE INVENTION

The present invention relates to herbicidal compositions comprising an aminophosphate or aminophosphonate salt, particularly to herbicidal compositions comprising a relatively high amount of aminophosphate or aminophosphonate salt and a betaine-based surfactant composition of matter.

Among various presentations of compositions comprising glyphosate, concentrated liquid compositions that can be diluted by the end-user (typically a farmer) are of interest. Usually, the higher the glyphosate concentration is, the better it is, because the end-user can set the use concentration (the amount of active applied to the field) by adjusting the dilution rate, and can avoid handling much product (for example the higher the concentration is, the lower the weight is).

Concentrated compositions can comprise a high amount of glyphosate, water, and at least one surfactant compound that can be useful as a formulation aid (dispersion, dissolution and/or stability of the glyphosate in water), and/or as a biological activator (for example increasing the efficacy of glyphosate salt, for example by encouraging wetting of a weed to be eliminated, or by encouraging penetration of the glyphosate into the weed). The amount of glyphosate, the nature of surfactant(s), the amount thereof, and possible further ingredients might have also an effect onto the rheological properties of the composition (for example viscosity, or ability to be spread), as such, or upon dilution. The rheological properties of the composition as such or upon dilution are important for handling and spreading purpose.

Where the concentration of glyphosate is high, crystallization is to be avoided. Crystallization can occur at different temperatures, at different glyphosate concentrations, or when diluting with water. The crystallization is characterized by formation of small solid particles comprising glyphosate. These small particles can have the bad impact of filters clogging, nozzles clogging, creating unnecessary hazardous waste problems to dispose off the crystals, loss of activity (bioefficacy), and/or bad repartition of the active on the field.

Compositions comprising glyphosate and ethoxylated fatty amines surfactants are known. However these compounds are believed to be rather ecotoxic, irritant or slightly biodegradable. There is a need for replacing these compounds or for reducing the amount thereof in the compositions.

Document WO 01/17358 (Monsanto) describes compositions comprising a high amount glyphosate isopropylamine salt and a mixture of surfactants comprising a surfactant of formula R—CO—NR′—(CR′₂)_(n)—COOM. The mixture of surfactants is taught enhancing herbicidal effectiveness. The surfactant is however expensive and there is a need for other solutions.

Document WO 03/063589 (Rhodia) describes compositions comprising 360 g/L of glyphosate isopropylamine salt (as glyphosate acid equivalent, 783 g/L as salt concentration), a betaine surfactant, and at least one further compound such as optionally ethoxylated amines or etheramines.

Document WO 01/17358 (Albright & Wilson) describes compositions comprising 360 g/L of glyphosate isopropylamine salt (as glyphosate acid equivalent), desalinated alkyl betaines or alkyl amidopropyl betaines surfactants, and optionally ether carboxylates. The document also describes compositions comprising 360 g/L of glyphosate isopropylamine, and alkyl betaines or alkyl amidopropyl betaines surfactants comprising 6 to 12 weight % NaCl. The document teaches that the stability of the composition is linked to presence inorganic salts and teaches that the total level of said inorganic salt is preferably of less than 0.39% by weight. The compositions having desalinated alkyl betaines or alkyl amidopropyl betaines surfactants are taught avoiding crystallization of glyphosate. However desalination is expensive. There is a need in less expensive compositions and/or in compositions comprising higher amounts of glyphosate that do not precipitate.

BRIEF SUMMARY OF THE INVENTION

The invention addresses at least one of the concerns above. Thus the invention relates to a herbicidal aqueous composition comprising:

at least 360 g/L of an aminophosphate or aminophosphonate salt, preferably a glyphosate or gluphosinate salt, at least 80 g/L, preferably at least 100 g/L, of a surfactant system comprising:

-   a betaine surfactant composition of matter comprising:     -   water,     -   a betaine having formula R¹R²R²N⁺—CH₂COO⁻, wherein:         -   R¹ is a linear or branched hydrocarbon group, preferably an             alkyl group containing 3 to 30 carbon atoms, preferably 3 to             20 carbon atoms,         -   R², identical or different, is a C₁-C₃ alkyl group,             preferably a methyl group, and     -   at least 1% by weight of a chloride based salt, preferably of a         potassium chloride salt, and -   optionally at least one surfactant different from the betaine of the     betaine surfactant composition of matter.

According to another aspect the invention relates to a process for preparing the herbicidal aqueous composition.

According to another aspect the invention relates to the use of the betaine surfactant composition of matter in a herbicidal aqueous composition comprising at least 360 g/L of an aminophosphate or aminophosphonate salt, preferably a glyphosate or gluphosinate salt.

According to another aspect the invention relates to the use of a surfactant system comprising the betaine surfactant composition of matter and optionally the different surfactant, in a herbicidal aqueous composition comprising at least 360 g/L of an aminophosphate or aminophosphonate salt, preferably a glyphosate or gluphosinate salt.

The invention also relates to the use of the composition.

DETAILED DESCRIPTION OF THE INVENTION Definitions

In the present specification, unless otherwise provided, the amounts of aminophosphate or aminophosphonate salt, preferably a glyphosate or gluphosinate salt salts are expressed as acid equivalents.

In the present specification, unless otherwise provided, the amounts of surfactant system or of betaine surfactant composition of matter, are the total amounts of a mixture or association (amounts “as is”), as opposed to amounts as active matter, dry matter amounts (solid content), or the like.

In the present specification, unless otherwise provided, the amounts of surfactant active matter, for a surfactant ingredient or system, for example the betaine surfactant composition of matter or the surfactant system, are defined as the dry matter amount of the surfactant ingredient or system, minus the total amount of salt in the surfactant ingredient or system.

In the present specification, “chloride based salts” refer to any salt having Cl⁻, particularly KCl or NaCl. The amounts thereof can be determined by conventional means. The amounts, unless otherwise provided relate to amounts by weight in the herbicidal composition.

In the present specification, “substantially no sodium cation” refers to amounts of sodium cations of lower than 1% by weight, preferably lower than 0.1%, preferably lower than 0.01%.

In the present specification, a “surfactant system” refers to an association or mixture of surfactants which are provided separately in the composition or as a mixture prepared before introduction.

Surfactants are usually reaction adducts comprising several different compounds. These different compounds have effects on the herbicidal composition. Hence it is referred to surfactant compositions of matter. Thus in the present specification a betaine surfactant composition of matter is understood as a mixture comprising water, a chlorine based salt, the betaine surfactant active molecule(s), and optionally further compounds such as pH buffers.

The ingredients of the composition are described below. Any combination thereof and therein can be implemented to defined, and/or prepare the composition according to the invention, and/or the uses according to the invention.

Aminophosphate or Aminophosphonate Salt

Aminophosphate or aminophosphonate salts are known by the one skilled in the art.

Preferred salts are glyphosate or gluphosinate salts.

Glyphosate refers to N-(phosphonomethyl)glycine.

Gluphosinate refers to 4-[hydroxy(methyl)phosphinoyl]-DL-homoalanine.

The salts include:

sodium (Na) salts; potassium (K) salts; ammonium salts having N(R)₄ ⁺ cations wherein R groups, identical or different, represent a hydrogen atom or a linear or non linear, saturated or unsaturated C₁-C₆ hydrocarbon group optionally substituted by a hydroxyl group, for example isopropylamine salts; sulphonium salts; said salts being present alone or in a combination.

Ammonium salts that can in particular be cited include salts obtained from secondary or primary amines such as isopropylamine (IPA), dimethylamine, diamines such as ethylenediamine, or alkanolamines such as monoethanolamine (MEA). Trimethylsulphonium is a perfectly suitable sulphonium salt.

Preferred glyphosate salts for herbicidal application that can be cited are isopropylamine (IPA) salt, monoethanolamine (MEA) salt, trimethylsulphonium salt, potassium salt, ammonium salt, and mixtures or associations thereof, for example as taught in documents WO01/26469 (Nufarm) and WO03/013241 (Nufarm).

In the present invention isopropylamine containing salts are preferred. Thus in a preferred embodiment the salt is a glyphosate isopropylamine salt. In a preferred embodiment, the ratio between the cation such as the cation of isopropylamine and glyphosate is of about 1/1. However the ratio can of higher than 1/1. Such a ratio provides compositions having higher pH. The higher the pH, the lower the crystallization. pH can be also managed by using any other basic compound, for example KOH or other buffers.

Surfactant System

The surfactant system comprises the betaine surfactant composition of matter and optionally at least one surfactant different from the betaine of the betaine surfactant composition of matter. The different surfactant(s) can be provided in the herbicidal composition as a separate ingredient; it can be thus referred to an association. In another embodiment, at least one of the different surfactant(s) can be provided as a mixture with the betaine surfactant composition of matter, it can be thus referred to a mixture or a blend. In that embodiment the different surfactant can be prepared separately and simply mixed with the betaine surfactant composition of matter, or prepared in the same course of process of the preparation of the betaine surfactant composition of matter. Some useful different surfactant(s) are described below as further ingredients and as further surfactants.

Betaine Surfactant Composition of Matter:

Surfactants are usually reaction adducts comprising several different compounds. These different compounds have effects on the herbicidal composition. Hence it is referred to surfactant composition of matter.

The betaine surfactant composition of matter comprises:

-   -   water,     -   a betaine having formula R¹R²R²N⁺−CH₂COO⁻, wherein:         -   R¹ is a linear or branched hydrocarbon group, preferably an             alkyl group containing 3 to 30 carbon atoms, preferably 3 to             20 carbon atoms,         -   R², identical or different, is a C₁-C₃ alkyl group,             preferably a methyl group,     -   at least 1% by weight of a chloride based salt, preferably of         potassium chloride salt.

The betaine is a main surfactant compound of the betaine surfactant composition of matter. It is preferably the main surfactant compound of the surfactant system. It is also referred to the main surfactant. By main surfactant compound it is meant that said surfactant compound represents the highest surfactant active matter compared to optional other surfactant(s). For example, in a mixture or association comprising 40 parts as active of surfactant 1, 30 parts as active of surfactant 2, and 30 parts as active of surfactant 3, surfactant 1 would be considered as main surfactant even if it represents lower than 50% of all surfactants.

Preferably the betaine active matter represents at least 30% by weight, preferably at least 50%, of the total surfactant active matter of the surfactant system in the composition.

Advantageously the betaine surfactant composition of matter comprises:

water, at least 25%, preferably at least 30%, by weight as active surfactant matter of the betaine, at least 2%, preferably at least 5%, by weight of a potassium chloride salt.

Preferably the betaine surfactant composition of matter comprises:

water, at least 30%, preferably at least 35% by weight as active surfactant matter of the betaine, at least 5% by weight of a potassium chloride salt, and substantially no sodium cation.

In a preferred embodiment, the total amount of inorganic salts in the surfactant system, preferably of chloride-based salts, is of higher than 0.4% by weight, and preferably higher than 1% by weight.

In a preferred embodiment, the amount of inorganic salts, preferably of chloride-based salts, is of higher than 8%, preferably higher than 10%, preferably higher than 12%, by weight of the amount of the betaine surfactant composition of matter.

In a preferred embodiment, the total amount of inorganic salts, preferably of chloride-based salts, is of higher than 8%, preferably higher than 10%, preferably higher than 12%, by weight of the amount of the surfactant system.

The betaine has preferably R² being a methyl group (alkyldimethylbetaines).

R¹ is an alkyl group. This group is usually actually a mixture of different groups having different numbers of carbon atoms, being linear or branched, and optionally having some insaturations. These mixtures come from the reagents used to prepare them, which are actually distillation cuts and/or have a natural origin. In the present specification the number of carbon atoms in the R¹ group refers to the number of carbon atoms of the two most represented species.

In a preferred embodiment:

R² is a methyl group, and R¹ is a lauryl alkyl group mixture, having more than 50% by weight of C₁₂.

The betaine surfactant composition of matter can be obtained by, and is preferably obtained from, a process comprising the following steps:

step 1) reacting a compound of formula R¹R²R²N with chloroacetic acid, to obtain a reaction product; step 2) adding potassium hydroxide to increase the pH, step 3) optionally adding some further ingredients or adjusting the concentration or pH.

It is mentioned that step 1 and step 2 can also be performed simultaneously, by adding potassium hydroxide during reaction completion or by adding progressively chloroacetic acid and potassium hydroxide.

In another embodiment potassium chloroacetate is used in step 1) instead of chloroacetic acid, and step 2) is optional.

In a preferred embodiment, the process does not comprise any desalination step or ion exchange step. Thus the process is cost effective, and therefore the herbicidal composition can also be cost interesting.

Advantageously, the pH of the betaine surfactant composition of matter is of from 6 to 8, in a 1% by weight water solution.

Further Ingredients

The herbicidal composition can comprise further ingredients, such as:

surfactants different from the betaine of the betaine surfactant composition of matter, as part of the surfactant system, anti-foaming agents, solvents, preferably water miscible solvent, preferably polar solvents, or deposition control agents such as anti-rebound or anti-drift agents, optionally added afterward.

The one skilled in the art knows further ingredients that can be used for managing some properties or features of the composition and/or for adding benefits.

The formulations can for example comprise for example:

organopolysiloxanes antifoaming agent; thickening agents such as xanthan gum type polysaccharides, alginates, carboxylated or hydroxylated methylcelluloses, synthetic macromolecules of the polyacrylate, polymaleate, polyvinylpyrrolidone, polyethylene glycol or polyvinyl alcohol type, or of the inorganic type such as bentonites. auxiliary additives such as antioxidants, anti-UV agents, colorants, etc. solvent such as an alcohol, for example isopropanol, typically up to 15% by weight.

The amount of these additives listed above is normally less than 10% by weight, preferably 1% by weight or less, advantageously 0.1% by weight or less compared with the composition weight.

Other Surfactants

The herbicidal composition can comprise a further surfactant, different from the betaine of the betaine surfactant composition matter. This further surfactant can provide further advantages or synergies in term of costs, and/or bioefficacy, and/or rheology management, and/or environment concerns and/or sensitivity concerns.

Examples of further surfactants include:

an ethoxylated fatty amine, a fatty amine, an ether carboxylate, an acid or non acid mono- and di-ester phosphate, optionally polyalkoxylated, an alkylmonoglycoside or alkylpolyglycoside, advantageously octylglycoside, an octylpolyclycoside, decylglycoside, a decylpolyglycoside, or a mixture thereof, or mixtures thereof.

The fatty amines or ethoxylated fatty amines can comprise at least one hydrocarbon group containing 2 to 24 carbon atoms, optionally polyalkoxylated.

The fatty amines or ethoxylated fatty amines can more particularly be selected from amines comprising at least one linear or branched, saturated or unsaturated group containing 2 to 24 carbon atoms, preferably 8 to 18 carbon atoms, optionally comprising 2 to 30 oxyethylene groups, or a mixture of a plurality thereof. Examples include ethoxylated tallow amines.

The fatty amines or ethoxylated fatty amines can be selected from ethoxylated fatty amines comprising at least one linear or branched, saturated or unsaturated groups containing 6 to 24 carbon atoms, preferably 8 to 20 carbon atoms, comprising 2 to 30 oxyethylene groups, or a mixture of a plurality thereof. Examples include the compounds having the following formula:

wherein R represents a linear or branched, saturated or unsaturated hydrocarbon group containing 6 to 24 carbon atoms, preferably 8 to 20 carbon atoms; OA represents an oxypropylene group; and n, n′, which may or may not be identical, represent a mean number in the range 1 to 30.

Examples of such amines that can be cited are amines derived from copra and containing 5 oxyethylene (OE) motifs, oleic amines containing 5 OE, amines derived from tallow containing 5-20 OE, for example 10, compounds corresponding to the above formula, in which R is an alkyl group containing 12 to 15 carbon atoms, the number of OE motifs being in the range 20 to 30.

The amount of fatty amines or ethoxylated fatty amines can be of from 0 (none) to 120 g/l of the composition, preferably of from 0 (none) to 60 g/l.

The ether carboxylate has preferably formula R(OCH₂CH₂)_(n)OCH₂CO₂ ⁻, wherein R is a linear or branched alkyl, alkenyl, alkylphenyl or polypropyleneoxy group having from 6 to 20, for example 8 to 14, aliphatic carbon atoms and n is of from 1 to 30, preferably of from 2 to 20. The ether carboxylate has preferably a counter ion being ammonium or potassium, or obtained from an amine or alkanolamine having up to 6 carbon atoms.

The acid or non acid mono- and di-ester phosphate, optionally polyalkoxylated is selected from acid or non acid phosphate mono- or di-esters, optionally polyalkoxylated, with the formula below:

(AO)_(3-m)P(═O)(OM)_(m)

wherein:

A, identical or different, represents a group R′¹—O(CH₂—CHR′²—O)_(n) wherein:

-   -   R′¹, identical or different, represents a linear or non linear,         saturated or unsaturated C₆-C₂₀ hydrocarbon group, preferably         C₈-C₁₈;     -   R′², identical or different, represents a hydrogen atom or a         methyl or ethyl group, preferably a hydrogen atom;     -   n is a mean number of motifs in the range 0 to 10, preferably in         the range 2 to 10;

M, identical or different, represents a hydrogen atom, an alkali or alkaline-earth metal, a N(R³)₄ ⁺ type radical wherein R³, identical or different, represents a hydrogen atom or a linear or non linear, saturated or unsaturated C₁-C₆ hydrocarbon group optionally substituted with a hydroxyl group;

m is a whole or average number in the range 1 to 2.

The acid or non acid mono- and di-ester phosphate, optionally polyalkoxylated can be in the form of a monoester, a diester, or a mixture of these two esters.

The amount of acid or non acid mono- and di-ester phosphate, optionally polyalkoxylated can be of from 0 (none) to 120 g/l of the composition.

Process for Preparing the Herbicidal Composition.

The compositions of the invention can be prepared by mixing their different constituents with moderate stirring.

This operation preferably takes place at a temperature in the range 15° C. to 60° C., preferably at a temperature close to ambient temperature (15-30° C.).

The surfactant composition of matter is preferably only added once the other constituents have been mixed.

Hence, a complete preferred process can comprise the following steps:

step a) preparing a surfactant composition of matter by a process comprising the following steps:

step 1) reacting a compound of formula R¹R²R²N with chloroacetic acid, to obtain a reaction product;

step 2) adding potassium hydroxide to increase the pH,

step 3) optionally adding some further ingredients or adjusting the concentration or pH.

step b) mixing the aminophosphate or aminophosphonate salt, the surfactant composition of matter and optionally further ingredients.

Step b) for example comprises the steps of providing a mixture of water and the aminophosphate or aminophosphonate salt, and then adding the surfactant composition of matter.

It is mentioned that step 1 and step 2 can also be performed simultaneously, by adding potassium hydroxide during reaction completion or by adding progressively chloroacetic acid and potassium hydroxide.

In another embodiment potassium chloroacetate is used in step 1) instead of chloroacetic acid, and step 2) is optional.

Herbicidal Composition Preferred Features

Advantageously, in the herbicidal composition, the total amount of surfactant active matter is of at least 24 g/L.

Advantageously, the surfactant active matter is of at least 25% by weight of the surfactant system. In other word, the surfactant system has at least 25% by weight as active surfactant matter of the betaine together with optional different surfactant(s).

Advantageously, the herbicidal composition comprises at least 80 g/L, preferably at least 100 g/L, of the betaine surfactant composition of matter. Thus the betaine surfactant composition of matter represents all of a part of the surfactant system in the herbicidal composition.

Advantageously, the herbicidal composition comprises:

from 360 g/L to 560 g/L of the aminophosphate or aminophosphonate salt, preferably of glyphosate salt, preferably glyphosate isopropylamine salt, and from 80 g/L to 160 g/L of the surfactant system, preferably of the betaine surfactant composition of matter.

Advantageously, the composition comprises:

from 400 to 500 g/L of glyphosate salt, preferably of glyphosate isopropylamine salt, and from 100 to 135 g/L of the surfactant system, preferably of the betaine surfactant composition of matter.

Preferably, the composition comprises:

at least 500 g/L of the glyphosate salt, preferably of glyphosate isopropylamine salt, and at least 120g/L, preferably at least 135 g/L, of the surfactant system, preferably of the betaine surfactant composition of matter.

Is it preferred that the total amount of inorganic salts in the composition, preferably of chloride-based salts, is of higher than 0.4% by weight, and preferably higher than 1% by weight.

At high loads of glyphosate salt, especially with salts different from potassium salts, for example with glyphosate isopropylamine salt, the invention allows among other handling less composition (higher load), with a good stability (no crystals) with an interesting bioefficacy and/or ecotoxic profile.

At low loads of glyphosate salt, especially with salts different from potassium salts, for example with glyphosate isopropylamine salt, the invention allows among other a good stability (no crystal) with an interesting bioefficacy and/or ecotoxic profile as the load of surfactant can be increased.

Downstream Use

The herbicidal composition of the invention can be thus used to treat plants, normally after diluting with water. The diluted composition can be applied onto a field by any appropriate mean.

The dilution, and the application onto the field, can be for example such that the amount of aminophosphate or amoniphosphonate salt, preferably glyphosate salt, is of from 500 g acid equivalent/ha to 1500 g acid equivalent/ha, typically from 600 to 1200 g/ha.

Upon dilution the end-user can admix other herbicides, pesticides, fertilizers, fungicides. For example the end-user can combine the glyphosate salt with other herbicides to address some weed-resistances to glyphosate. The composition according to the invention, especially with glyphosate salt different from potassium salt, for example with glyphosate isopropylamine salt, provides a good compatibility with other herbicides. The invention can allow high loads of glyphosate salts with good compatibility.

Some details or advantages of the invention will appear in the non-imitative examples below.

EXAMPLES

The following ingredients are used:

Surfactant 1: surfactant composition of matter comprising the following:

-   -   Alkyldimethylbetaine, wherein the alkyl is a mixture of about 70         weight % lauryl (C₁₂) and of about 30 weight % tetradecyl (C₁₄),     -   Solids: about 41 weight %     -   KCl: about 9 weight %         Surfactant 2: Mirataine D40, marketed by Rhodia         Surfactant 3: Terwet 3780 Tallow amine ethoxylate, Hunstman         Glyphosate: Glyphosate isopropylamine salt (46% of acid         equivalent by weight)

The following compositions are prepared (C stands for comparative, ae stands for acid equivalent).

Example 1 2 3C 4C Glyphosate (ae) 450 g/L 510 g/L 450 g/L 450 g/L Surfactant 1 120 g/L 140 g/L (amount as is) Surfactant 2 120 g/L (amount as is) Surfactant 3 120 g/L pH 4.5 as 7% 4.5 as 7% 4.5 as 7% solution solution solution Aspect No No Some Not stable crystals crystals crystals This shows that the composition according to the invention have a surprising good stability, without crystals formation.

Meanwhile the compositions according to the examples have a better (lower fresh weight) and/or quicker bio-efficacy (higher brownout) on at least some significant weeds (annual ryegrass and wild radish). 

1-22. (canceled)
 23. A herbicidal aqueous composition comprising: (i) at least 360 g/L of an aminophosphate or aminophosphonate salt; (ii) at least 80 g/L of a surfactant system which comprises: a betaine surfactant composition comprising: water, a betaine having the formula R¹R²R²N⁺—CH₂COO⁻, wherein: R¹ is a linear or branched hydrocarbon radical having 3 to 30 carbon atoms the radicals R², which may be identical or different, are each a C₁-C₃ alkyl radical, at least 1% by weight of a chloride salt, and (iii) optionally, at least one surfactant other than the betaine of the betaine surfactant composition.
 24. The herbicidal composition as defined by claim 23, wherein the total amount of surfactant is at least 24 g/L.
 25. The herbicidal composition as defined by claim 23, wherein the surfactant active agent comprises at least 25% by weight of the surfactant system.
 26. The herbicidal composition as defined by claim 23, wherein the betaine active agent constitutes at least 30% by weight of the total surfactant active agent in the surfactant system.
 27. The herbicidal composition as defined by claim 23, comprising at least 80 g/L of the betaine surfactant composition.
 28. The herbicidal composition as defined by claim 23, wherein the betaine surfactant composition comprises: water, at least 25% by weight as active surfactant agent of the betaine, at least 2% by weight of a potassium chloride salt.
 29. The herbicidal composition as defined by claim 23, wherein the betaine surfactant composition comprises: water, at least 30% by weight as active surfactant agent of the betaine, at least 5% by weight of a potassium chloride salt, and substantially no sodium cation.
 30. The herbicidal composition as defined by claim 23, wherein the total amount of inorganic salts is greater than 0.4% by weight.
 31. The herbicidal composition as defined by claim 23, wherein the total amount of inorganic salts in the surfactant system is greater than 0.4% by weight.
 32. The herbicidal composition as defined by claim 23, wherein the amount of inorganic salts is greater than 8% by weight of the amount of the betaine surfactant composition.
 33. The herbicidal composition as defined by claim 23, wherein the total amount of inorganic salts is greater than 8% by weight of the amount of the surfactant system.
 34. The herbicidal composition as defined by claim 23, comprising a glyphosate isopropylamine salt.
 35. The herbicidal composition as defined by claim 23, comprising from 360 g/L to 560 g/L of the aminophosphate or aminophosphonate salt, and from 80 g/L to 160 g/L of the surfactant system.
 36. The herbicidal composition as defined by claim 23, comprising from 400 to 500 g/L of glyphosate isopropylamine salt, and from 100 to 135 g/L of the surfactant system.
 37. The herbicidal composition as defined by claim 23, comprising at least 500 g/L of glyphosate isopropylamine salt, and at least 120 g/L of the surfactant system.
 38. The herbicidal composition as defined by claim 23, wherein said betaine R² is a methyl group, and R¹ is a lauryl alkyl radical mixture.
 39. The herbicidal composition as defined by claim 23, wherein the betaine surfactant composition is obtained by a process comprising the following steps: step 1) reacting a compound of formula R¹R²R²N with chloroacetic acid, to obtain a reaction product; step 2) adding potassium hydroxide to increase the pH, step 3) optionally, adding further ingredients or adjusting the concentration or pH.
 40. The herbicidal composition as defined by claim 23, wherein the pH of the betaine surfactant composition ranges from 6 to 8, in a 1% by weight water solution.
 41. The herbicidal composition as defined by claim 23, further comprising: surfactant(s) other than the betaine of the betaine surfactant composition, anti-foaming agents, solvents, deposition control or anti-rebound or anti-drift agents, optionally added subsequently.
 42. The herbicidal composition as defined by claim 41, wherein the surfactant other than the betaine of the betaine surfactant composition comprises: an ethoxylated fatty amine, an ether carboxylate, an acid or non acid mono- or di-ester phosphate, optionally polyalkoxylated, an alkylmonoglycoside or alkylpolyglycoside, or mixtures thereof.
 43. A process for formulating a herbicidal composition as defined by claim 23, comprising the following steps: step a) preparing a betaine surfactant composition by a process comprising the following steps: step 1) reacting a compound of formula R¹R²R²N with chloroacetic acid, to obtain a reaction product, step 2) adding potassium hydroxide to increase the pH, step 3) optionally adding further ingredients or adjusting the concentration or pH. step b) mixing the aminophosphate or aminophosphonate salt, the betaine surfactant composition and the optional further ingredients.
 44. The process as defined by claim 43, wherein step b) comprises the steps of providing a mixture of water and the glyphosate salt, and then adding the betaine surfactant composition. 